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Studies on the effect of mode of delivery on the renin‐angiotensin system in mother and fetus at term
Author(s) -
TETLOW HAZEL J.,
PIPKIN FIONA BROUGHTON
Publication year - 1983
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/j.1471-0528.1983.tb08612.x
Subject(s) - umbilical vein , vaginal delivery , renin–angiotensin system , fetus , medicine , umbilical artery , plasma renin activity , placenta , vein , caesarean section , venous blood , endocrinology , pregnancy , obstetrics , blood pressure , chemistry , biology , biochemistry , in vitro , genetics
Summary. Plasma renin substrate (PRS) and renin (PRC) concentrations were measured in the paired umbilical artery and vein blood of 54 babies and in the venous blood of 23 of their mothers at vaginal delivery. Similar samples were collected from 31 babies and their mothers at elective caesarean section. Fetal renin concentrations in both umbilical artery and vein blood were markedly increased at vaginal delivery compared with values at operative delivery. Renin substrate concentration was correlated with the length of second stage of labour. Umbilical vein PRC and PRS were greater than corresponding umbilical artery values at vaginal, but not at operative delivery, suggesting that some factor associated with delivery might stimulate the placenta to produce renin and renin substrate during vaginal delivery. Maternal and umbilical concentrations of both renin and renin substrate were unrelated, supporting the view that the maternal and fetal compartments are independent. It is suggested that hyperactivity of the renin‐angiotensin system may be an integral part of the marked changes in cardiovascular homeostasis which occur at birth.